Today, most metrology machines for gears (and other toothed articles) and/or gear cutting tools comprise a computer-controlled electro-mechanical multi-axis system. FIG. 1, for example, shows the architecture of a known metrology system. The application software (for example, GAMA software commercially available from Gleason Metrology Systems) provides the interface to the end user to program the gear parameters, select tests and set other parameters to perform a gear inspection. It also generates required machine move commands and communicates to the control program. The control software (i.e. control program) acts as the intermediary between the application software and the rest of the system. Once the requested commands are executed, the control program provides data, such as axis positions and probe deflections, back to the application software which analyzes the information provided by the control program and provides easy-to-read charts and inspection reports to the user.
The control program is a piece of software that takes the commands from the application software and converts into commands that can be sent to the motion control hardware (MC). The control program generates the target positions for each of the machine axes along with desired velocities and sends them to the MC which generates the motion profile for each individual axis, based on certain motion parameters (such as acceleration, jerk, etc.) and interpolates as necessary. The MC card is linked to AC servo drives on a motion control network (i.e. communication network) using an interface such as SERCOS, for example. The MC generates the commands for the servo drives which in turn send the signals to the motors. When the motors move the mechanical axes, the feedback devices (e.g. glass scales) attached to the mechanical axis generate a signal to indicate the current position of all the axes (linear and rotary). The drives perform the closed-loop control for each command received from the MC until the target position is reached. The control program receives the current position of the axes at any instant via the MC.
A three dimensional (i.e. 3D) scanning probe is attached to an axis (e.g. the X-axis) of a gear metrology machine which is driven to make physical contact with a gear placed on a rotary table of the machine. The control software reads the probe deflections (for example, in mutually perpendicular X, Y and Z directions of the probe) via a counter card plugged into a PCI slot on the machine computer (i.e. the PC). The counter card receives the probe deflections via an interpolator unit connected to the probe. The control software ensures that the axes positions and probe deflections are synchronized and provides all the data back to the application software.
As shown in the FIG. 1, the application software and the control software run on a PC (e.g. off-the-shelf industrial PC) running Windows OS for example. Preferably, both application and control programs are written in VB.Net but any appropriate software programming language and operating system combination may be utilized. The MC and the counter card are plugged into the PCI slots inside the PC. Normally, a monitor and a keyboard/mouse attached to the PC act as user input devices.
The PC resides in an electrical control cabinet of the machine (see FIG. 2b) along with the drives and other electrical and electronic components. The operator station (FIG. 2a), which includes the monitor 3 and printer, is usually located outside the machine allowing easy access to the operator. While the application software provides the interface to create part programs and other machine settings required to inspect gears, there are a few manual operations that require a different interface. An example of this is an operator panel which allows the user to manually effect (i.e. jog) movement along or about an axis manually. The operator panel 2 shown in FIG. 3, has two joysticks 4, 6. A first joystick 4 controls X and Y axes and the other joystick 6 controls Z and rotary (A) axes. There is an axis selector switch 8 to allow the users to jog only one axis at a time. This helps the user to have more control when manually jogging one axis by preventing inadvertent movement of other axes. Another control 10 on the panel controls the jogging speed. There are two buttons 12, 14 on the operator panel. Button 12 turns the drives ON and button 14 clears and/or resets any faults generated by the system. In addition, there is an E-STOP 16 to stop the machine in case of emergencies.
FIG. 4 shows how the operator panel may be interfaced to the machine. The joysticks are connected to the PC via USB interface. The control software reads and deciphers the signals from the joysticks and generates appropriate motion commands and sends them to MC. There is an Input/Output (I/O) device/hardware in the system that is controlled by the control software (in some instances, the MC card may provide a few I/O ports). The axis selector, feedrate control and other switches (or LEDs) are connected to the control program via the I/O interface. The control program reads the inputs and modifies the motion commands as necessary. The operator panel described by FIG. 4 is attached to the machine and is not moveable (see also FIG. 2a).
There are different sizes of gear metrology machines to provide the capacity to inspect different size gears. For example, a product line may include machines with gear diameter capacity ranging from 175 mm to 3000 mm or more. As the machine size increases, the operator often will have to climb on the machine to access the gear on the rotary table. An operator panel attached to the machine is cumbersome to use in such instances and there is a need for a remote pendant that the operator can carry along and use for jogging the machine axes as needed.
A prior art example of one such a device is shown in FIG. 5. In this device, a remote joystick controller (RJC) 18 connects to the PC via a USB interface and communicates with the Control Program similar to the joysticks on the operator panel. The RJC also has the axis select and feedrate control features that the operator panel features. Such a RJC device has been offered on gear metrology machines. While the RJC offers the remote jogging capability, the users of gear metrology machines would benefit from additional functionality offered on a remote device.
US 2010/0039391 to Spink et al. discloses a pendant for programming and controlling a coordinate measuring machine (CMM). The pendant comprises one or more microprocessors and is capable of controlling a CMM directly. The pendant is effectively a computer by itself running firmware on dedicated electronic hardware embedded inside the pendant. The pendant also provides a full-fledged graphical user interface (GUI) which is configurable by the end user and is intended to be a sole interface to the user. The GUI is created on the pendant and is available only on the pendant.
There exists a need for an enhanced, simpler and less expensive pendant whereby the productivity of a metrology machine can be improved.